phx21 and EPA Method 21

Method 21	phx21 Features
6.1 The VOC instrument detector shall respond to the compounds being processed. Detector types that may meet this requirement include, but are not limited to, catalytic oxidation, flame ionization, infrared absorption, and photoionization.	phx21 uses a Flame Ionization detector.
6.2 The instrument shall be capable of measuring the leak definition concentration specified in the regulation.	phx21 has an accurate range of 0-50,000 ppm.
6.3 The scale of the instrument meter shall be readable to ±2.5 percent of the specified leak definition concentration.	phx21 displays one tenth of 1ppm.
6.4 The instrument shall be equipped with an electrically driven pump to ensure that a sample is provided to the detector at a constant flow rate. The nominal sample flow rate, as measured at the sample probe tip, shall be 0.10 to 3.0 l/min (0.004 to 0.1 ft3/min) when the probe is fitted with a glass wool plug or filter that may be used to prevent plugging of the instrument.	phx21 uses pump throttling to maintain a constant flow rate of 1.25 liters per min regardless of probe lenght and partial filter obstruction.
6.5 The instrument shall be equipped with a probe or probe extension for sampling not to exceed 6.4 mm (1/4 in) in outside diameter, with a single end opening for admission of sample.	phx21 uses a .225 inch metal probe tip.
6.6 The instrument shall be intrinsically safe for operation in explosive atmospheres as defined by the National Electrical Code by the National Fire Prevention Association or other applicable regulatory code for operation in any explosive atmospheres that may be encountered in its use. The instrument shall, at a minimum, be intrinsically safe for Class 1, Division 1 conditions, and/or Class 2, Division 1 conditions, as appropriate, as defined by the example code. The instrument shall not be operated with any safety device, such as an exhaust flame arrestor, removed.	phx21 has been certified intrinsically safe. Class 1 Division 1 Groups ABCD Temperature Rating T4. Documentation of this certification can be found on LDARtools.com
8.1.3.2 The instrument response time shall be equal to or less than 30 seconds. The instrument pump, dilution probe (if any), sample probe, and probe filter that will be used during testing shall all be in place during the response time determination.	phx21 has an average response time of under 3 seconds.
8.1.1.3 Alternatively, if response factors have been published for the compounds of interest for the instrument or detector type, the response factor determination is not required, and existing results may be referenced. Examples of published response factors for flame ionization and catalytic oxidation detectors are included in References 1-3 of Section 17.0.	Because phx21 uses an FID, currently published response factors for the TVA can be used. For a list of these FID response factors see LDARtools.com.